Here's a tip you should file away in your folder for zombie apocalypse preparation and in your brain for future conversations for whoa, I didn't know it was that easy: opening a can without a can opener. All it takes is some abrasive concrete rubbing of the can's top and a firm squeeze of the can's body. As long as you don't slice your finger when the can opens, you could eat some tasty everlasting goop anytime you want.